Influence of End Plates on Rotational Oscillations of a Rectangular Cylinder

2020 ◽  
Author(s):  
R. Shmigirilov ◽  
A. Ryabinin
Keyword(s):  
Rectangular Cylinder ◽  
Rotational Oscillations

scholarly journals The Turbulent Flow over the BARC Rectangular Cylinder: A DNS Study

2021 ◽  
Author(s):  
Alessandro Chiarini ◽  
Maurizio Quadrio
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Direct Numerical Simulation ◽  
Finite Differences ◽  
Turbulence Models ◽  
Fine Tuning ◽  
Rectangular Cylinder ◽  
Budget Equation ◽  
Complete Set ◽  
First Time

AbstractA direct numerical simulation (DNS) of the incompressible flow around a rectangular cylinder with chord-to-thickness ratio 5:1 (also known as the BARC benchmark) is presented. The work replicates the first DNS of this kind recently presented by Cimarelli et al. (J Wind Eng Ind Aerodyn 174:39–495, 2018), and intends to contribute to a solid numerical benchmark, albeit at a relatively low value of the Reynolds number. The study differentiates from previous work by using an in-house finite-differences solver instead of the finite-volumes toolbox OpenFOAM, and by employing finer spatial discretization and longer temporal average. The main features of the flow are described, and quantitative differences with the existing results are highlighted. The complete set of terms appearing in the budget equation for the components of the Reynolds stress tensor is provided for the first time. The different regions of the flow where production, redistribution and dissipation of each component take place are identified, and the anisotropic and inhomogeneous nature of the flow is discussed. Such information is valuable for the verification and fine-tuning of turbulence models in this complex separating and reattaching flow.

Aerodynamic admittance of a 5:1 rectangular cylinder in turbulent flow

2019 ◽  
Vol 189 ◽  
pp. 125-134 ◽  
Author(s):  
Yang Yang ◽  
Mingshui Li ◽  
Yi Su ◽  
Yanguo Sun
Keyword(s):  
Turbulent Flow ◽  
Rectangular Cylinder

The Signal Generated by an Insect in a Spider's Web

1965 ◽  
Vol 43 (1) ◽  
pp. 185-192
Author(s):  
D. A. PARRY
Keyword(s):  
Linear Response ◽  
Wave Form ◽  
Irregular Wave ◽  
Prey Recognition ◽  
Upper Limit ◽  
Fast Transients ◽  
Sudden Release ◽  
House Spider ◽  
Rotational Oscillations ◽  
The Web

1. There is evidence that web-spinning spiders discriminate between prey and artifacts in their webs, and that the signal involved is a mechanical one. As a contribution to our understanding of the basis of this discrimination, an analysis has been made of the natural signal generated by an insect in the web of the British house spider Tegenaria atrica. 2. The signal investigated was frequency-limited to 1 kc./sec, this being the upper limit of the linear response of the specially designed transducer. 3. The signal has an irregular wave-form with most of the energy lying below 50 cyc./sec. Damped transverse and rotational oscillations of the mass of the spider in the compliance of the web have been recognized. In addition there are ‘fast transients’, most likely due to the sudden release of tension in the web by slight movements of the insect. 4. The possibility that the fast transients form the basis of prey-recognition is being investigated.

2D and 2.5D Numerical Simulations for Vortex-Induced Vibration (VIV) of a 1.5:1 Rectangular Cylinder

2021 ◽  
Author(s):  
Bowen Yan ◽  
Yangjin Yuan ◽  
Dalong Li ◽  
Ke Li ◽  
Qingshan Yang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Numerical Simulations ◽  
Phase Difference ◽  
Vortex Shedding ◽  
Lift Force ◽  
Small Scale ◽  
Aerodynamic Damping ◽  
Displacement Response ◽  
Wind Speeds ◽  
Rectangular Cylinder

The semi-periodic vortex-shedding phenomenon caused by flow separation at the windward corners of a rectangular cylinder would result in significant vortex-induced vibrations (VIVs). Based on the aeroelastic experiment of a rectangular cylinder with side ratio of 1.5:1, 2-dimensional (2D) and 2.5-dimensional (2.5D) numerical simulations of the VIV of a rectangular cylinder were comprehensively validated. The mechanism of VIV of the rectangular cylinder was in detail discussed in terms of vortex-induced forces, aeroelastic response, work analysis, aerodynamic damping ratio and flow visualization. The outcomes showed that the numerical results of aeroelastic displacement in the cross-wind direction and the vortex-shedding procedure around the rectangular cylinder were in general consistence with the experimental results by 2.5D numerical simulation. In both simulations, the phase difference between the lift and displacement response increased with the reduced wind speed and the vortex-induced resonance (VIR) disappeared at the phase difference of approximately 180∘. The work done by lift force shows a close relationship with vibration amplitudes at different reduced wind speeds. In 2.5D simulations, the lift force of the rectangular cylinder under different wind speeds would be affected by the presence of small-scale vortices in the turbulence flow field. Similarly, the phase difference between lift force and displacement response was not a constant with the same upstream wind speed. Aerodynamic damping identified from the VIV was mainly dependent on the reduced wind speed and negative damping ratios were revealed at the lock-in regime, which also greatly influenced the probability density function (PDF) of wind-induced displacement.

Sign in / Sign up

Export Citation Format

Share Document